Experimental study of stability and transition of supersonic boundary layer on swept wing at mach number 2-4

The paper is devoted to an experimental study of the laminar-turbulent transition and the instability disturbances evolution in a three-dimensional (3D) supersonic boundary layer on a swept wing with sharp and blunted leading edges at M = 2-4. The detailed data of the natural disturbances development are obtained. Characteristic zones of disturbances evolution are determined. It is found that for Mach numbers 2 and 2.5 measurements can be performed in the region of the linear stage of disturbances evolution, and the experimental data can be compared with the results of the calculations on the linear stability theory. The destabilization effect of leading edge bluntness was obtained. The statistical analysis and the analysis of amplitude-frequency spectra confirmed the existence of the mechanism of a secondary instability and its features were revealed in the supersonic flow of a swept wing.